Self-light-emitting apparatus and semiconductor device used in the apparatus

Abstract

The present invention relates to a semiconductor device formed in a self-light-emitting apparatus having a substrate and a plurality of self-light-emitting elements formed on the substrate, the semiconductor device being used to drive one of the self-light-emitting elements. The semiconductor device includes an active layer of semiconductor material, in which a source region and a drain region are formed, a source electrode having a multi-layered structure including an upper side layer of titanium nitride and a lower side layer of a high melting point metal having low resistance, the source electrode electrically being coupled to the source region, a drain electrode having a multi-layered structure including an upper side layer of titan nitride and a lower side layer of a high melting point metal having low resistance, the source electrode electrically being coupled to said drain region, an insulation layer formed on the active layer, and a gate electrode formed on the insulation layer.

What is claimed is:  
     
       1. An electroluminescent display device comprising: 
       a substrate having an insulating surface;  
       a thin film transistor formed over said substrate, said thin film transistor comprising a semiconductor island including source, drain and channel regions, and a gate electrode adjacent to said channel region with a gate insulating film interposed therebetween;  
       a first interlayer insulating film formed over said thin film transistor and said substrate;  
       an opening formed in said first interlayer insulating film to define a pixel region of said electroluminescent display device;  
       a pixel electrode electrically connected to the drain of said thin film transistor and formed in at least said opening of the first interlayer insulating film,  
       an electroluminescence layer formed on said pixel electrode; and  
       a counter electrode formed on said electroluminescence layer.  
     
     
       2. The electroluminescent display device according to  claim 1  further comprising a second interlayer insulating film formed on said first interlayer insulating film. 
     
     
       3. The electroluminescent display device according to  claim 1  wherein said electroluminescence layer comprises an organic electroluminescence layer. 
     
     
       4. The electroluminescent display device according to  claim 1  wherein said electroluminescence layer comprises an inorganic electroluminescence layer. 
     
     
       5. An electroluminescent display device comprising: 
       a substrate having an insulating surface;  
       a thin film transistor formed over said substrate, said thin film transistor comprising a semiconductor island including source, drain and channel regions, and a gate electrode adjacent to said channel region with a gate insulating film interposed therebetween;  
       a first interlayer insulating film formed over said thin film transistor and said substrate;  
       an opening formed in said first interlayer insulating film wherein said opening does not overlap said semiconductor island of the thin film transistor;  
       a pixel electrode electrically connected to the drain of said thin film transistor and formed in at least said opening of the first interlayer insulating film,  
       an electroluminescence layer formed on said pixel electrode; and  
       a counter electrode formed on said electroluminescence layer.  
     
     
       6. The electroluminescent display device according to  claim 5  further comprising a second interlayer insulating film formed on said first interlayer insulating film. 
     
     
       7. The electroluminescent display device according to  claim 5  wherein said electroluminescence layer comprises an organic electroluminescence layer. 
     
     
       8. The electroluminescent display device according to  claim 5  wherein said electroluminescence layer comprises an inorganic electroluminescence layer. 
     
     
       9. An electroluminescent display device comprising: 
       a substrate having an insulating surface:  
       a thin film transistor formed over said substrate, said thin film transistor comprising a semiconductor island including source, drain and channel regions, and a gate electrode adjacent to said channel region with a gate insulating film interposed therebetween;  
       a drain electrode in contact with said drain region;  
       a first interlayer insulating film formed over said thin film transistor, said drain electrode and said substrate;  
       a wiring formed on said first interlayer insulating film and electrically connected to the source region of said thin film transistor through a contact hole of said first interlayer insulating film; and  
       an opening formed in said first interlayer insulating film to expose a portion of said drain electrode;  
       a pixel electrode formed in said opening and connected to said exposed portion of the drain electrode;  
       an electroluminescence layer formed on said pixel electrode; and  
       a counter electrode formed on said electroluminescence layer.  
     
     
       10. The electroluminescent display device according to  claim 9  wherein said drain electrode comprises a first layer comprising a metal which directly contacts said drain region and a second layer comprising titanium nitride which directly contacts said pixel electrode, said metal selected from the group consisting of tungsten, molybdenum, tantalum, titanium and nickel. 
     
     
       11. The electroluminescent display device according to  claim 9  further comprising a second interlayer insulating film formed on said first interlayer insulating film. 
     
     
       12. The electroluminescent display device according to  claim 9  wherein said electroluminescence layer comprises an organic electroluminescence layer. 
     
     
       13. The electroluminescent display device according to  claim 9  wherein said electroluminescence layer comprises an inorganic electroluminescence layer.